Jansen reported to spring training Wednesday but won't immediately start a throwing program due to general lat soreness, Alex Speier of The Boston Globe reports.

EDGE Analysis

Everything initially appeared to be in order after the veteran closer's individual workout Wednesday morning, but Boston GM Craig Breslow then announced the lat injury. It's believed to be a mild issue, but coming into spring training with a new injury is always a concerning development. Jansen said he hopes to being throwing in about a week, per Gabrielle Starr of the Boston Herald.